ITO/nano‐Ag plasmonic window applied for efficiency improvement of near‐ultraviolet light emitting diodes

Abstract

In this study, to enhance the emission efficiency of GaN‐based near‐ultraviolet light‐emitting diodes (NUV‐LEDs), the ITO/nano‐Ag plasmonic window which possessed localized surface plasmon (LSP) coupling effect was prepared on the roughened p‐GaN layer. The LSP coupling was generated on the grating nanostructure, resulting from the spin‐coated Ag nanoparticles onto the p‐GaN layer. To obtain an obvious LSP coupling, the Ag nanoparticles should be distributed on the p‐GaN uniformly. Thus, the p‐GaN layer was treated via the Ar‐plasma treatment, and it confirmed an uniform distribution of Ag nanoparticles can be prepared on the p‐GaN. The light output power (@350 mA) of the surface‐plasmon‐enhanced NUV‐LED (SPE‐NUV‐LED) with the Ar‐plasma treated p‐GaN possessed 73.7% improvement compared with that of the conventional NUV‐LED (C‐NUV‐LED). This improvement can be attributed to the formation of LSP effect in Ag nanoparticles embedded in the roughened p‐GaN, resulting from the coupling between the excitons in MQWs and the LSP in Ag nanoparticles.